Note: This is the third of an eight-part series, going division by division through the NFL.

One effect of the lockout is that teams don't have as good a feel for their roster as they would in normal years. No one has conducted OTAs, rookies haven't had a chance to study the playbooks or meet with position coaches and because free agency was pushed back until after the lockout, many teams don't know what their rosters will look like, even as they begin training camp. So without further ado, let's look biggest remaining question for all four teams in the AFC North.

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Going back to 2008, our game-charting database shows one consistent tendency of John Harbaugh's offense: reliance on play-action passing. In Brian Billick's last season as head coach, Baltimore ranked 20th in play-action passing frequency. Since hiring Harbaugh, they've been the most play-action-reliant passing offense in the NFL, ranking first, third, and first in 2008, 2009, and 2010, respectively.

Strategically speaking, the play-action pass is all about deception. It requires the defense to read and react to a run, and at least one receiver capable of exploiting that mental error. With Ray Rice, newly signed fullback Vonta Leach, and a powerful run-blocking offensive line, Baltimore definitely has a good enough running game to achieve the first part. The question for 2011 is whether or not they have the second.

For the past three seasons, the ageless Derrick Mason was that receiver on the outside, and -- when healthy -- Todd Heap was that player down the seam. Both are no longer with the team. In fact, of their top four pass-catchers in 2010, the lowest of the four in yards per catch is the only one who remains on the roster: Anquan Boldin.